Merge remote-tracking branches 'spi/fix/ep93xx', 'spi/fix/rockchip', 'spi/fix/sunxi...

[cascardo/linux.git] / drivers / hwmon / dell-smm-hwmon.c

diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index c8bd3fd..2ac87d5 100644 (file)
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -73,6 +73,7 @@ static u32 i8k_hwmon_flags;
 static uint i8k_fan_mult = I8K_FAN_MULT;
 static uint i8k_pwm_mult;
 static uint i8k_fan_max = I8K_FAN_HIGH;
+static bool disallow_fan_type_call;
 
 #define I8K_HWMON_HAVE_TEMP1   (1 << 0)
 #define I8K_HWMON_HAVE_TEMP2   (1 << 1)
@@ -237,14 +238,28 @@ static int i8k_get_fan_speed(int fan)
 /*
  * Read the fan type.
  */
-static int i8k_get_fan_type(int fan)
+static int _i8k_get_fan_type(int fan)
 {
        struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
 
+       if (disallow_fan_type_call)
+               return -EINVAL;
+
        regs.ebx = fan & 0xff;
        return i8k_smm(&regs) ? : regs.eax & 0xff;
 }
 
+static int i8k_get_fan_type(int fan)
+{
+       /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
+       static int types[2] = { INT_MIN, INT_MIN };
+
+       if (types[fan] == INT_MIN)
+               types[fan] = _i8k_get_fan_type(fan);
+
+       return types[fan];
+}
+
 /*
  * Read the fan nominal rpm for specific fan speed.
  */
@@ -726,6 +741,9 @@ static struct attribute *i8k_attrs[] = {
 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
                              int index)
 {
+       if (disallow_fan_type_call &&
+           (index == 9 || index == 12))
+               return 0;
        if (index >= 0 && index <= 1 &&
            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
                return 0;
@@ -775,13 +793,17 @@ static int __init i8k_init_hwmon(void)
        if (err >= 0)
                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
 
-       /* First fan attributes, if fan type is OK */
-       err = i8k_get_fan_type(0);
+       /* First fan attributes, if fan status or type is OK */
+       err = i8k_get_fan_status(0);
+       if (err < 0)
+               err = i8k_get_fan_type(0);
        if (err >= 0)
                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
 
-       /* Second fan attributes, if fan type is OK */
-       err = i8k_get_fan_type(1);
+       /* Second fan attributes, if fan status or type is OK */
+       err = i8k_get_fan_status(1);
+       if (err < 0)
+               err = i8k_get_fan_type(1);
        if (err >= 0)
                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
 
@@ -937,12 +959,14 @@ static struct dmi_system_id i8k_dmi_table[] __initdata = {
 
 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
 
-static struct dmi_system_id i8k_blacklist_dmi_table[] __initdata = {
+/*
+ * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
+ * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
+ * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
+ * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
+ */
+static struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initdata = {
        {
-               /*
-                * CPU fan speed going up and down on Dell Studio XPS 8000
-                * for unknown reasons.
-                */
                .ident = "Dell Studio XPS 8000",
                .matches = {
                        DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
@@ -950,16 +974,19 @@ static struct dmi_system_id i8k_blacklist_dmi_table[] __initdata = {
                },
        },
        {
-               /*
-                * CPU fan speed going up and down on Dell Studio XPS 8100
-                * for unknown reasons.
-                */
                .ident = "Dell Studio XPS 8100",
                .matches = {
                        DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
                },
        },
+       {
+               .ident = "Dell Inspiron 580",
+               .matches = {
+                       DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
+               },
+       },
        { }
 };
 
@@ -974,8 +1001,7 @@ static int __init i8k_probe(void)
        /*
         * Get DMI information
         */
-       if (!dmi_check_system(i8k_dmi_table) ||
-           dmi_check_system(i8k_blacklist_dmi_table)) {
+       if (!dmi_check_system(i8k_dmi_table)) {
                if (!ignore_dmi && !force)
                        return -ENODEV;
 
@@ -986,6 +1012,9 @@ static int __init i8k_probe(void)
                        i8k_get_dmi_data(DMI_BIOS_VERSION));
        }
 
+       if (dmi_check_system(i8k_blacklist_fan_type_dmi_table))
+               disallow_fan_type_call = true;
+
        strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
                sizeof(bios_version));
        strlcpy(bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),